Comment: The challenges and opportunities from a STEP change in fusion power

Delivering fusion energy is one of, if not the, great engineering challenges of the era, says Paul Methven, STEP Programme Director, UKAEA.


It is vital for the planet as we strive to de-carbonise, and it is an enormous opportunity for those countries and companies that are in the vanguard of delivery.

Fusion has great potential to deliver safe, sustainable, low carbon energy for generations to come. Sometimes described as the ultimate energy source owing to its incredible power density, it is based on the same processes that power the sun and stars.  But realising those processes on Earth is hard. 

We need the best engineers and scientists, working collaboratively to come up with new solutions, and we need the best in complex programme delivery to join this endeavour to help translate those innovative solutions into reality, at pace.  That should excite and motivate anyone with an interest in doing something that really matters.

For STEP to be a success, it needs a huge dose of national ambition blended with international talent and tenacity. We are aiming to not only create a true fusion energy plant prototype, but to stimulate the emerging fusion energy industry and secure a strong UK lead in that. 

A prototype is not enough – we need to set the conditions for commercial fusion beyond that to provide a critical new energy source that will work alongside renewables and other technologies to achieve and maintain the low carbon economy of the future.


The path to commercially viable fusion energy is untrodden. We are spawning an entirely new global industry and are proud the UK is leading the way.

As a programme created by the UK Atomic Energy Authority (UKAEA), STEP, or Spherical Tokamak for Energy Production, will become a global hub for a wide range of engineering, technological and scientific expertise, leading to massive economic opportunities for the community in which it’s located, the wider region and the UK as a whole.

STEP aims to deliver a fully integrated fusion energy plant prototype capable of supplying electricity to the grid, showing the way for subsequent commercial plants that can supply our ever-growing electricity demands and also supply high grade heat to help de-carbonise complex industrial processes.

It will be an infrastructure project on a similar size and scale to Hinkley Point C, the UK’s current fission new build programme, or to ITER, the fusion experimental machine currently under construction in the South of France. To achieve this, we need to work with industry to ensure we have the range of skills we’ll need to design and build the plant.

Since the programme began in 2019, we have worked to develop a preferred basis of design for the plant, which is now being iterated to full concept design baseline by March 2024. In addition, we have completed a process to select a site, with our recommendations recently submitted for consideration by the Secretary of State at the Department of Business, Energy and Industrial Strategy (BEIS).  And we are developing the operating model for the programme – how we will work with industry in a collaborative construct, potentially led by a new bespoke delivery body focussed solely on this mammoth task.

At the same time, the government has been considering the appropriate regulatory framework for fusion energy, with findings from a consultation in Autumn 2021 due to be published shortly. This is likely to recommend a similar regulatory framework to that already in place at UKAEA’s Culham campus near Oxford.  The significantly lower hazards of fusion compared with fission offer a great opportunity to deliver safety in a cost-effective way, supporting fusion energy’s development and global deployment.

The next step for us is to begin to engage industry at scale.  We aim to bring two Whole Plant Partners on board to work alongside us from the end of 2023 – one focusing on engineering and the other on construction, who, together with UKAEA as the “Fusion Partner” providing deep fusion expertise built over decades of operations, will form an integrated delivery team. 

We are spawning an entirely new global industry and are proud the UK is leading the way

We will also engage several System Partners who will work with that integrated team on design and delivery of the myriad of complex systems needed for a fusion plant to work.  We are taking lessons from complex mega projects in many sectors to try and set us up for success. 

In an inherently uncertain and ground-breaking programme that’s a challenge, but it’s also a great opportunity to think about how best to do things and not to be overly constrained by the norms we may have become used to. 

Delivering fusion energy demands innovation and drive in both engineering and programme delivery, and we want to work with people who see things that way.  UKAEA’s procurement pipeline is the place to go for early notification of these opportunities.

STEP is targeting first operations around 2040 and, as well as demonstrating fusion energy is possible and can be commercially viable, the programme will provide a huge market stimulus, driving and supporting the supply chain to grow capability for fusion programmes worldwide, as well as creating spin offs in adjacent industries. 

STEP is likely to create hundreds of jobs during the detailed design phase, many thousands of jobs during construction and several hundred long-term, high-quality jobs during operation and post-operation.

Following site announcement, we’ll work with the local community to partner academia, develop an apprentice training scheme, and begin establishing our at-site presence well in advance of construction activities. To find out more, email:

Paul Methven, STEP Programme Director, UKAEA